Citation: Nielsen, K.; Norrestam, R.; Thorup, N.; Sotofte, I. (1989). Structural investigations of two synthetic oxyborates: The mixed magnesium-manganese and the pure cobalt ludwigites, Mg1.93(2) Mn1.07(2) O2 B O3 and Co3 O2 B O3. Zeitschrift fuer Kristallographie (149,1979-), 189, pp. 33-41.